It’s tricky to find a shoe shop that tries to help you with ‘fit’ rather than just selling you whichever ones you like the look of!
There used to be specialist running-shoe shops that would offer the option of you walking / running on a treadmill with a camera to film your gait, and how your feet move in different shoes - and the sorts of support that might be more suitable for you. I’m not sure if there’s anywhere like that near you? Or if it would help?